Using mice, the researchers were able to identify a special pattern of nerve cell activity that is responsible for the re-occurrence of these abnormally strong memories. The researchers suggest that a possible explanation as to why certain unwanted memories are abnormally strong may be because those memories leverage the large-scale cooperation between multiple brain regions. The researchers chose to focus on cocaine experience to model salient experience that alters behaviour; and one with obvious implications. But at the other end of the spectrum are abnormally powerful memories, which are characterised by unfiltered information processing. Strong memories that can drive inappropriate actions are seen in a wide range of brain conditions, such as drug addiction or post-traumatic stress disorders.